How do i read a delimited text file in python?

What is the best and easiest way to read the text file delimited by tab in python? I want to convert first column of text file into a list escaping first line [header].

import csv
with open ['data.txt', 'r'] as f:
    first_row = [column[0] for column in csv.reader[f,delimiter='\t']]
    print [first_row]

The code above gives all the elements of first_column. How can I escape first line [header]?

asked Jun 12, 2013 at 1:51

lisalisa

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2

Maybe I'm missing something in the question, but why not just slice off the first element of the list?

import csv
with open ['data.txt', 'r'] as f:
    first_column = [row[0] for row in csv.reader[f,delimiter='\t']]
    print [first_column[1:]]

answered Jun 12, 2013 at 2:04

Dave CostaDave Costa

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0

Once you load the file, you can access data by column name. In this example, FirstColName is the first column name of the loaded file.

import pandas as pd
import numpy as np

file = pd.read_csv[r"C:\Users\hydro\a.txt", sep='\t']
firstCol = np.asarray[file.FirstColName]
print [firstCol]

answered Dec 12, 2017 at 14:51

SubhashiSubhashi

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Learning Objectives

In this challenge we are going to focus on accessing a text file in Python to read the content of the file line by line.

Challenge

Your first challenge consists of writing a Python script that will read the following text file, one line at a time and display the content of each line on screen.

To read the content of a text file line by line we are going to use a for loop that will loop through and extract each line of the text file one at a time. It will stop looping only once the it will have reached the last line.

Check this animation that explains this process:

When the text file uses a CSV format [Comma Separtred Values], each line contains several values separated using a special character, often a comma or a semi-colon. In this case we can use the split[] method to extract each value of each line and store them in a list.

Check this animation that explains this process further:

Solution

The solutions below contains 5 main steps:

1. Step 1: Open the text file using the open[] function. This function takes two parameters: The name of the file [e.g. “playlist.txt”] and the access mode. In our case we are opening the file in read-only mode: “r”.
2. Read through the file one line at a time using a for loop.
3. Split the line into an array. This is because in this file each value is separated with a semi-column. By splitting the line we can then easily access each value [field] individually.
4. Output the content of each field using the print method.
5. Once the for loop is completed, close the file using the close[] method.

Main Access Modes when opening a file with the open[] function.

Your Challenge

Use what you have learnt in this blogbpost to complete these challenges:
My mp3 playlist[Reading a text file using Python] US Population[Reading a text file using Python]

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